# Custom Datatypes

## Unofficial Draft20 March 2018

Editors:
(Armines Fayol)
(Armines Fayol)

This document is also available in these non-normative formats: Turtle RDF document (text/turtle) and Javascript specification code (application/javascript)

## Abstract

This document specifies custom datatypes designed to concisely encode important information.

## Status of This Document

This document is draft of a potential specification. It has no official standing of any kind and does not represent the support or consensus of any standards organisation.

## 1. Custom Datatypes for Quantity Values

Being able to describe quantity values and their unit is a requirement that is common for many applications in several industrial sectors such as manufacturing, transport and logistics, personal and public health, smart cities, energy, environment, buildings, agriculture. Different ontologies have been developed to describe units, their relations, and quantities with their values.

We propose an alternative approach based on RDF Datatypes, that leverages the Unified Code of Units of Measures, a code system intended to include \emph{all} units of measures being contemporarily used in international science, engineering, and business..

The custom datatypes introduced in this section can be used for lightweight encoding and querying of quantity values, in a wide range of applications where representing and reasoning with quantity kinds and values is more important than reasoning with units.

### 1.1 Overview of Datatypes

This section is non-normative.

Main datatype: cdt:ucum

### 1.2 cdt:ucum

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#ucum

Definition UCUM Datatype - Datatype to encode measurements in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a unit chosen in the The Unified Code for Units of Measure code system. Set of measures, or quantity values as defined by the International Systems of Quantities. Maps lexical forms with a UCUM unit to their corresponding measures according to the International Systems of Quantities. Check out the playground For example, all literals below are well formed, test them online and share the same value. Example 1"1 m"^^cdt:ucum "1.0e+9 nm"^^cdt:ucum "1e+10 Ao"^^cdt:ucum "1 m/s.s"^^cdt:ucum

### 1.3 cdt:acceleration

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#acceleration

Definition acceleration Datatype - Datatype to encode measurement of quantity kind acceleration in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an acceleration unit chosen in the The Unified Code for Units of Measure code system Set of acceleration as defined by the International Systems of Quantities. Maps lexical forms with a acceleration unit to their corresponding acceleration measures according to the International Systems of Quantities. For example, all acceleration literals below are well formed, test them online. Example 2"1 m/s2 "^^cdt:acceleration # S.I. "3.8 [g]"^^cdt:acceleration # standard acceleration of free fall "1.57e-2 cm/s2"^^cdt:acceleration # S.I. equiv. of Gal "1.57e-2 Gal"^^cdt:acceleration # Gal

### 1.4 cdt:amountOfSubstance

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#amountOfSubstance

Definition amountOfSubstance Datatype - Datatype to encode measurement of quantity kind amountOfSubstance in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an amountOfSubstance unit chosen in the The Unified Code for Units of Measure code system Set of amountOfSubstance as defined by the International Systems of Quantities. Maps lexical forms with a amountOfSubstance unit to their corresponding amountOfSubstance measures according to the International Systems of Quantities. For example, the amountOfSubstance literal below is well formed. Example 3"1.2 mol"^^cdt:amountOfSubstance

### 1.5 cdt:angle

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#angle

Definition angle Datatype - Datatype to encode measurement of quantity kind angle in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an angle unit chosen in the The Unified Code for Units of Measure code system Set of angle as defined by the International Systems of Quantities. Maps lexical forms with a angle unit to their corresponding angle measures according to the International Systems of Quantities. For example, all angle literals below are well formed, test them online. Example 4"360 deg"^^cdt:angle # degree "1 '"^^cdt:angle # minute "1 ''"^^cdt:angle # second "1 rad"^^cdt:angle # radian "1 circ"^^cdt:angle # circle 

### 1.6 cdt:area

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#area

Definition area Datatype - Datatype to encode measurement of quantity kind area in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an area unit chosen in the The Unified Code for Units of Measure code system Set of area as defined by the International Systems of Quantities. Maps lexical forms with a area unit to their corresponding area measures according to the International Systems of Quantities. For example, all area literals below are well formed, test them online. Example 5"1 m2"^^cdt:area # square meter "1 ar"^^cdt:area # are "1 [sin_i]"^^cdt:area # square inch International customary units "1 [in_i]2"^^cdt:area # square inch International customary units "1 [smi_us]"^^cdt:area # square mile Older U.S. “survey” lengths (also called "statute" lengths)

### 1.7 cdt:catalyticActivity

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#catalyticActivity

Definition catalyticActivity Datatype - Datatype to encode measurement of quantity kind catalyticActivity in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a catalyticActivity unit chosen in the The Unified Code for Units of Measure code system Set of catalyticActivity as defined by the International Systems of Quantities. Maps lexical forms with a catalyticActivity unit to their corresponding catalyticActivity measures according to the International Systems of Quantities. For example, all catalyticActivity literals below are well formed, test them online. Example 6"1 mol/s"^^cdt:catalyticActivity # mole per second "1 kat"^^cdt:catalyticActivity # KATAL "1 U"^^cdt:catalyticActivity # Unit

### 1.8 cdt:dimensionless

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#dimensionless

Definition dimensionless Datatype - Datatype to encode measurement of quantity kind dimensionless in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a dimensionless unit chosen in the The Unified Code for Units of Measure code system Set of dimensionless as defined by the International Systems of Quantities. Maps lexical forms with a dimensionless unit to their corresponding dimensionless measures according to the International Systems of Quantities. For example, all dimensionless literals below are well formed, test them online. Example 7"1 "^^cdt:dimensionless # Unit (empty string) "1 [pi]"^^cdt:dimensionless # pi "1 %"^^cdt:dimensionless # percent "1 [ppth]"^^cdt:dimensionless # parts per thousand "1 [ppm]"^^cdt:dimensionless # parts per million "1 [ppb]"^^cdt:dimensionless # parts per billion "1 [pptr]"^^cdt:dimensionless # parts per trillion

### 1.9 cdt:electricCapacitance

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#electricCapacitance

Definition electricCapacitance Datatype - Datatype to encode measurement of quantity kind electricCapacitance in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an electricCapacitance unit chosen in the The Unified Code for Units of Measure code system Set of electricCapacitance as defined by the International Systems of Quantities. Maps lexical forms with a electricCapacitance unit to their corresponding electricCapacitance measures according to the International Systems of Quantities. For example, all electricCapacitance literals below are well formed, test them online. Example 8"1 C/V"^^cdt:electricCapacitance # coulomb per volt "1 F"^^cdt:electricCapacitance # farad 

### 1.10 cdt:electricCharge

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#electricCharge

Definition electricCharge Datatype - Datatype to encode measurement of quantity kind electricCharge in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an electricCharge unit chosen in the The Unified Code for Units of Measure code system Set of electricCharge as defined by the International Systems of Quantities. Maps lexical forms with a electricCharge unit to their corresponding electricCharge measures according to the International Systems of Quantities. For example, all electricCharge literals below are well formed, test them online. Example 9"1 C"^^cdt:electricCharge # coulomb "1 [e]"^^cdt:electricCharge # elementary charge 

### 1.11 cdt:electricConductance

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#electricConductance

Definition electricConductance Datatype - Datatype to encode measurement of quantity kind electricConductance in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an electricConductance unit chosen in the The Unified Code for Units of Measure code system Set of electricConductance as defined by the International Systems of Quantities. Maps lexical forms with a electricConductance unit to their corresponding electricConductance measures according to the International Systems of Quantities. For example, all electricConductance literals below are well formed, test them online. Example 10"1 /Ohm"^^cdt:electricConductance # inverse of Ohm "1 Ohm-1"^^cdt:electricConductance # inverse of Ohm "1 S"^^cdt:electricConductance # siemens 

### 1.12 cdt:electricCurrent

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#electricCurrent

Definition electricCurrent Datatype - Datatype to encode measurement of quantity kind electricCurrent in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an electricCurrent unit chosen in the The Unified Code for Units of Measure code system Set of electricCurrent as defined by the International Systems of Quantities. Maps lexical forms with a electricCurrent unit to their corresponding electricCurrent measures according to the International Systems of Quantities. For example, all electricCurrent literals below are well formed, test them online. Example 11"1 C/s"^^cdt:electricCurrent # coulomb per second "1 A"^^cdt:electricCurrent # ampère "1 mA"^^cdt:electricCurrent # milliampère "1 Bi"^^cdt:electricCurrent # Biot 

### 1.13 cdt:electricInductance

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#electricInductance

Definition electricInductance Datatype - Datatype to encode measurement of quantity kind electricInductance in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an electricInductance unit chosen in the The Unified Code for Units of Measure code system Set of electricInductance as defined by the International Systems of Quantities. Maps lexical forms with a electricInductance unit to their corresponding electricInductance measures according to the International Systems of Quantities. For example, all electricInductance literals below are well formed, test them online. Example 12"1 Wb/A"^^cdt:electricInductance # weber per ampère "1 V.s/A"^^cdt:electricInductance # volt second per ampère "1 H"^^cdt:electricInductance # henry 

### 1.14 cdt:electricPotential

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#electricPotential

Definition electricPotential Datatype - Datatype to encode measurement of quantity kind electricPotential in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an electricPotential unit chosen in the The Unified Code for Units of Measure code system Set of electricPotential as defined by the International Systems of Quantities. Maps lexical forms with a electricPotential unit to their corresponding electricPotential measures according to the International Systems of Quantities. For example, all electricPotential literals below are well formed, test them online. Example 13"230.7 V"^^cdt:electricPotential "2.307e2 V"^^cdt:electricPotential ".2307 kV"^^cdt:electricPotential ".2307 J/C"^^cdt:electricPotential

### 1.15 cdt:electricResistance

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#electricResistance

Definition electricResistance Datatype - Datatype to encode measurement of quantity kind electricResistance in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an electricResistance unit chosen in the The Unified Code for Units of Measure code system Set of electricResistance as defined by the International Systems of Quantities. Maps lexical forms with a electricResistance unit to their corresponding electricResistance measures according to the International Systems of Quantities. For example, all electricResistance literals below are well formed, test them online. Example 14"1 V/A"^^cdt:electricResistance "1 Ohm"^^cdt:electricResistance # Ohm "1 kOhm"^^cdt:electricResistance # kiloOhm "1 mOhm"^^cdt:electricResistance # milliOhm "1 MOhm"^^cdt:electricResistance # MegaOhm

### 1.16 cdt:energy

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#energy

Definition energy Datatype - Datatype to encode measurement of quantity kind energy in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an energy unit chosen in the The Unified Code for Units of Measure code system Set of energy as defined by the International Systems of Quantities. Maps lexical forms with a energy unit to their corresponding energy measures according to the International Systems of Quantities. For example, all energy literals below are well formed, test them online. Example 15"1 kg.m2/s2"^^cdt:energy # S.I. unit for energy "1 N.m"^^cdt:energy # Newton meter "1 W.s"^^cdt:energy # Watt second "1 kW.h"^^cdt:energy # kiloWatt hour "1 erg "^^cdt:energy # erg "1 eV"^^cdt:energy # electronvolt "1 J"^^cdt:energy # joule "1 cal"^^cdt:energy # calorie "1 [Cal]"^^cdt:energy # nutrition label Calories

### 1.17 cdt:force

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#force

Definition force Datatype - Datatype to encode measurement of quantity kind force in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a force unit chosen in the The Unified Code for Units of Measure code system Set of force as defined by the International Systems of Quantities. Maps lexical forms with a force unit to their corresponding force measures according to the International Systems of Quantities. For example, all force literals below are well formed, test them online. Example 16"1 kg.m/s2"^^cdt:force # S.I. equiv. of Newton "1 N"^^cdt:force # Newton "1 gf"^^cdt:force # gram-force "1 g.[g]"^^cdt:force # definition of gram-force "1 dyn"^^cdt:force # dyne "1 g.cm/s2"^^cdt:force # S.I. equiv. of dyne

### 1.18 cdt:frequency

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#frequency

Definition frequency Datatype - Datatype to encode measurement of quantity kind frequency in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a frequency unit chosen in the The Unified Code for Units of Measure code system Set of frequency as defined by the International Systems of Quantities. Maps lexical forms with a frequency unit to their corresponding frequency measures according to the International Systems of Quantities. For example, all frequency literals below are well formed, test them online. Example 17"1 Hz"^^cdt:frequency # Hertz "1 MHz"^^cdt:frequency # MegaHertz "1 s-1"^^cdt:frequency # per second "1 /s"^^cdt:frequency # per second "1 1/s"^^cdt:frequency # per second

### 1.19 cdt:illuminance

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#illuminance

Definition illuminance Datatype - Datatype to encode measurement of quantity kind illuminance in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and an illuminance unit chosen in the The Unified Code for Units of Measure code system Set of illuminance as defined by the International Systems of Quantities. Maps lexical forms with a illuminance unit to their corresponding illuminance measures according to the International Systems of Quantities. For example, all illuminance literals below are well formed, test them online. Example 18"1 lm/m2"^^cdt:illuminance # lumen per square meter "1 lx"^^cdt:illuminance # lux "1 ph"^^cdt:illuminance # phot

### 1.20 cdt:length

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#length

Definition length Datatype - Datatype to encode measurement of quantity kind length in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a length unit chosen in the The Unified Code for Units of Measure code system Set of length as defined by the International Systems of Quantities. Maps lexical forms with a length unit to their corresponding length measures according to the International Systems of Quantities. For example, all length literals below are well formed, test them online. Example 19"1 km"^^cdt:length "1.609344E+6 mm"^^cdt:length "5280 [ft_i]"^^cdt:length

### 1.21 cdt:luminousFlux

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#luminousFlux

Definition luminousFlux Datatype - Datatype to encode measurement of quantity kind luminousFlux in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a luminousFlux unit chosen in the The Unified Code for Units of Measure code system Set of luminousFlux as defined by the International Systems of Quantities. Maps lexical forms with a luminousFlux unit to their corresponding luminousFlux measures according to the International Systems of Quantities. For example, all luminousFlux literals below are well formed, test them online. Example 20"1 lm"^^cdt:luminousFlux # lumen

### 1.22 cdt:luminousIntensity

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#luminousIntensity

Definition luminousIntensity Datatype - Datatype to encode measurement of quantity kind luminousIntensity in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a luminousIntensity unit chosen in the The Unified Code for Units of Measure code system Set of luminousIntensity as defined by the International Systems of Quantities. Maps lexical forms with a luminousIntensity unit to their corresponding luminousIntensity measures according to the International Systems of Quantities. For example, all luminousIntensity literals below are well formed, test them online. Example 21"1 cd"^^cdt:luminousIntensity # candela

### 1.23 cdt:magneticFlux

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#magneticFlux

Definition magneticFlux Datatype - Datatype to encode measurement of quantity kind magneticFlux in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a magneticFlux unit chosen in the The Unified Code for Units of Measure code system Set of magneticFlux as defined by the International Systems of Quantities. Maps lexical forms with a magneticFlux unit to their corresponding magneticFlux measures according to the International Systems of Quantities. For example, all magneticFlux literals below are well formed, test them online. Example 22"1 Wb"^^cdt:magneticFlux # weber

### 1.24 cdt:magneticFluxDensity

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#magneticFluxDensity

Definition magneticFluxDensity Datatype - Datatype to encode measurement of quantity kind magneticFluxDensity in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a magneticFluxDensity unit chosen in the The Unified Code for Units of Measure code system Set of magneticFluxDensity as defined by the International Systems of Quantities. Maps lexical forms with a magneticFluxDensity unit to their corresponding magneticFluxDensity measures according to the International Systems of Quantities. For example, all magneticFluxDensity literals below are well formed, test them online. Example 23"1 Wb/m2"^^cdt:magneticFluxDensity # weber per square meter "1 T"^^cdt:magneticFluxDensity # tesla "1 G"^^cdt:magneticFluxDensity # gauss

### 1.25 cdt:mass

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#mass

Definition mass Datatype - Datatype to encode measurement of quantity kind mass in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a mass unit chosen in the The Unified Code for Units of Measure code system Set of mass as defined by the International Systems of Quantities. Maps lexical forms with a mass unit to their corresponding mass measures according to the International Systems of Quantities. For example, all mass literals below are well formed, test them online. Example 24"1 g"^^cdt:mass # gram "1 kg"^^cdt:mass # kilogram "1 t"^^cdt:mass # tonne "1 u"^^cdt:mass # unified atomic mass unit "1 [m_e]"^^cdt:mass # electron mass "1 [gr]"^^cdt:mass # grain (avoirdupois weight system) "1 [oz_av]"^^cdt:mass # ounce (avoirdupois weight system)

### 1.26 cdt:power

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#power

Definition power Datatype - Datatype to encode measurement of quantity kind power in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a power unit chosen in the The Unified Code for Units of Measure code system Set of power as defined by the International Systems of Quantities. Maps lexical forms with a power unit to their corresponding power measures according to the International Systems of Quantities. For example, all power literals below are well formed, test them online. Example 25"1 J/s"^^cdt:power # joule per second "1 W"^^cdt:power # watt "1 [ft_i].[lbf_av]/s"^^cdt:power # definition of horse power "1 [HP]"^^cdt:power # horsepower

### 1.27 cdt:pressure

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#pressure

Definition pressure Datatype - Datatype to encode measurement of quantity kind pressure in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a pressure unit chosen in the The Unified Code for Units of Measure code system Set of pressure as defined by the International Systems of Quantities. Maps lexical forms with a pressure unit to their corresponding pressure measures according to the International Systems of Quantities. For example, all pressure literals below are well formed, test them online. Example 26"1 Pa"^^cdt:pressure # pascal "1 bar"^^cdt:pressure # bar "1 atm"^^cdt:pressure # standard atmosphere "1 att"^^cdt:pressure # technical atmosphere

Definition radiationDoseAbsorbed Datatype - Datatype to encode measurement of quantity kind radiationDoseAbsorbed in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a radiationDoseAbsorbed unit chosen in the The Unified Code for Units of Measure code system Set of radiationDoseAbsorbed as defined by the International Systems of Quantities. Maps lexical forms with a radiationDoseAbsorbed unit to their corresponding radiationDoseAbsorbed measures according to the International Systems of Quantities. For example, all radiationDoseAbsorbed literals below are well formed, test them online. Example 27"1 erg/g"^^cdt:radiationDoseAbsorbed # erg per gram "1 RAD"^^cdt:radiationDoseAbsorbed # radiation absorbed dose

Definition radiationDoseEffective Datatype - Datatype to encode measurement of quantity kind radiationDoseEffective in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a radiationDoseEffective unit chosen in the The Unified Code for Units of Measure code system Set of radiationDoseEffective as defined by the International Systems of Quantities. Maps lexical forms with a radiationDoseEffective unit to their corresponding radiationDoseEffective measures according to the International Systems of Quantities. For example, all radiationDoseEffective literals below are well formed, test them online. Example 28"1 J/kg"^^cdt:radiationDoseEffective # Joule per kilogram "1 Sv"^^cdt:radiationDoseEffective # sievert

Definition radioactivity Datatype - Datatype to encode measurement of quantity kind radioactivity in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a radioactivity unit chosen in the The Unified Code for Units of Measure code system Set of radioactivity as defined by the International Systems of Quantities. Maps lexical forms with a radioactivity unit to their corresponding radioactivity measures according to the International Systems of Quantities. For example, all radioactivity literals below are well formed, test them online. Example 29"1 s-1"^^cdt:radioactivity # per second "1 Bq"^^cdt:radioactivity # becquerel "1 Ci"^^cdt:radioactivity # Curie 

### 1.31 cdt:solidAngle

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#solidAngle

Definition solidAngle Datatype - Datatype to encode measurement of quantity kind solidAngle in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a solidAngle unit chosen in the The Unified Code for Units of Measure code system Set of solidAngle as defined by the International Systems of Quantities. Maps lexical forms with a solidAngle unit to their corresponding solidAngle measures according to the International Systems of Quantities. For example, all solidAngle literals below are well formed, test them online. Example 30"1 sr"^^cdt:solidAngle # steradian "1 sph"^^cdt:solidAngle # sphere

### 1.32 cdt:speed

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#speed

Definition speed Datatype - Datatype to encode measurement of quantity kind speed in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a speed unit chosen in the The Unified Code for Units of Measure code system Set of speed as defined by the International Systems of Quantities. Maps lexical forms with a speed unit to their corresponding speed measures according to the International Systems of Quantities. For example, all speed literals below are well formed, test them online. Example 31"120 m/s"^^cdt:speed # meter per second "90 km/h"^^cdt:speed # kilometer per hour "90 km.h-1"^^cdt:speed # kilometer per hour

### 1.33 cdt:temperature

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#temperature

Definition temperature Datatype - Datatype to encode measurement of quantity kind temperature in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a temperature unit chosen in the The Unified Code for Units of Measure code system Set of temperature as defined by the International Systems of Quantities. Maps lexical forms with a temperature unit to their corresponding temperature measures according to the International Systems of Quantities. For example, all temperature literals below are well formed, test them online. Example 32"273.15 K"^^cdt:temperature # kelvin "37.5 Cel"^^cdt:temperature # degree Celsius "100 [degF]"^^cdt:temperature # degree Fahrenheit "100 [degR]"^^cdt:temperature # degree Rankine "100 [degRe]"^^cdt:temperature # degree Réaumur 

### 1.34 cdt:time

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#time

Definition time Datatype - Datatype to encode measurement of quantity kind time in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a time unit chosen in the The Unified Code for Units of Measure code system Set of time as defined by the International Systems of Quantities. Maps lexical forms with a time unit to their corresponding time measures according to the International Systems of Quantities. For example, all time literals below are well formed, test them online. Example 33"1 ns"^^cdt:time # nanosecond "1 s"^^cdt:time # second "1 min"^^cdt:time # minute "1 h"^^cdt:time # hour "1 d"^^cdt:time # day "1 a_t"^^cdt:time # tropical year "1 a_j"^^cdt:time # mean Julian year "1 a_g"^^cdt:time # mean Gregorian year "1 a"^^cdt:time # year "1 wk"^^cdt:time # week "1 mo_s"^^cdt:time # synodal month "1 mo_j"^^cdt:time # mean Julian month "1 mo_g"^^cdt:time # mean Gregorian month "1 mo"^^cdt:time # month

### 1.35 cdt:volume

RDF Datatype with IRI: http://w3id.org/lindt/custom_datatypes#volume

Definition volume Datatype - Datatype to encode measurement of quantity kind volume in a simple literal. Concatenation of the lexical form of an xsd:decimal, optionally followed by e or E and the lexical form of an xsd:integer, at least one space, and a volume unit chosen in the The Unified Code for Units of Measure code system Set of volume as defined by the International Systems of Quantities. Maps lexical forms with a volume unit to their corresponding volume measures according to the International Systems of Quantities. For example, all volume literals below are well formed, test them online. Example 34"1 L"^^cdt:volume # liter "1 dm3"^^cdt:volume "1 m3"^^cdt:volume # cubic meter "1 m.m.m"^^cdt:volume # cubic meter "100 [cin_i]"^^cdt:volume # cubic inch (International customary units) "100 [gal_br]"^^cdt:volume # gallon (British Imperial volumes) "100 [pt_br]"^^cdt:volume # pint (British Imperial volumes)

## 2. Implementation

### 2.1 On Apache Jena

Features

• Overload of SPARQL operators (=, <, etc.) to compare measurement literals;
• Overload of algebraic function (+, -, *, /) to manipulate measurement literals:
• Add two commensurable measurement literals
• Subtract a measurement literals to a commensurable one
• Multiply two measurement literals, or a measurement literal and a scalar (xsd:int, xsd:decimal, xsd:float, xsd:double)
• Divide a measurement literal by a measurement literal, a measurement literal by a scalar, or a scalar by a measurement literal
• Custom SPARQL function with IRI: http://w3id.org/lindt/custom_datatypes#sameDimension(arg1, arg2) to check if two measurement literals are commensurable (returns a xsd:boolean).
• Cast to XSD numeric datatypes: Test it online.